feat: add stateful HTTP/3 negotiation with probe and cooldown

common/constant/key.go

@@ -160,6 +160,8 @@ const (
 	CallHTTP2                          = "http2"
 	CallHTTP3                          = "http3"
 	CallHTTP2AndHTTP3                  = "http2-and-http3"
+	AltSvcProtocolH2                   = "h2"
+	AltSvcProtocolH3                   = "h3"
 	ServiceInfoKey                     = "service-info"
 	RpcServiceKey                      = "rpc-service"
 	ClientInfoKey                      = "client-info"

protocol/triple/client.go

@@ -314,72 +314,3 @@ func genKeepAliveOptions(url *common.URL, tripleConf *global.TripleConfig) ([]tr
 
 	return cliKeepAliveOpts, keepAliveInterval, keepAliveTimeout, nil
 }
-
-// dualTransport is a transport that can handle both HTTP/2 and HTTP/3
-// It uses HTTP Alternative Services (Alt-Svc) for protocol negotiation
-type dualTransport struct {
-	http2Transport *http2.Transport
-	http3Transport *http3.Transport
-	// Cache for alternative services to avoid repeated lookups
-	altSvcCache *tri.AltSvcCache
-}
-
-// newDualTransport creates a new dual transport that supports both HTTP/2 and HTTP/3
-func newDualTransport(tlsConfig *tls.Config, keepAliveInterval, keepAliveTimeout time.Duration) http.RoundTripper {
-	http2Transport := &http2.Transport{
-		TLSClientConfig: tlsConfig,
-		ReadIdleTimeout: keepAliveInterval,
-		PingTimeout:     keepAliveTimeout,
-	}
-
-	http3Transport := &http3.Transport{
-		TLSClientConfig: tlsConfig,
-		QUICConfig: &quic.Config{
-			KeepAlivePeriod: keepAliveInterval,
-			MaxIdleTimeout:  keepAliveTimeout,
-		},
-	}
-
-	return &dualTransport{
-		http2Transport: http2Transport,
-		http3Transport: http3Transport,
-		altSvcCache:    tri.NewAltSvcCache(),
-	}
-}
-
-// RoundTrip implements http.RoundTripper interface with HTTP Alternative Services support
-func (dt *dualTransport) RoundTrip(req *http.Request) (*http.Response, error) {
-	// Check if we have cached alternative service information
-	cachedAltSvc := dt.altSvcCache.Get(req.URL.Host)
-
-	// If we have valid cached alt-svc info and it's for HTTP/3, try HTTP/3 first
-	// Check if the cached information is still valid (not expired)
-	if cachedAltSvc != nil && cachedAltSvc.Protocol == "h3" {
-		logger.Debugf("Using cached HTTP/3 alternative service for %s", req.URL.String())
-		resp, err := dt.http3Transport.RoundTrip(req)
-		if err == nil {
-			// Update alt-svc cache from response headers
-			dt.altSvcCache.UpdateFromHeaders(req.URL.Host, resp.Header)
-			return resp, nil
-		}
-		logger.Debugf("Cached HTTP/3 request failed to %s, falling back to HTTP/2: %v", req.URL.String(), err)
-	}
-
-	// Start with HTTP/2 to get alternative service information
-	logger.Debugf("Making initial HTTP/2 request to %s to discover alternative services", req.URL.String())
-	resp, err := dt.http2Transport.RoundTrip(req)
-	if err != nil {
-		logger.Errorf("HTTP/2 request failed to %s: %v", req.URL.String(), err)
-		return nil, err
-	}
-
-	// Check for alternative services in the response
-	dt.altSvcCache.UpdateFromHeaders(req.URL.Host, resp.Header)
-
-	// If the response indicates HTTP/3 is available, try HTTP/3 for future requests
-	if altSvc := dt.altSvcCache.Get(req.URL.Host); altSvc != nil && altSvc.Protocol == "h3" {
-		logger.Debugf("Server %s supports HTTP/3, will use HTTP/3 for future requests", req.URL.Host)
-	}
-
-	return resp, nil
-}